Apparatus for annealing thin steel sheets



S. PEACOCK.

APPARATUS FOR ANNEALING THIN STEEL SHEETS.

APPLICATION FILED NOV. 9, 920. 1 ,427,3 1 9, Patented Aug. 29, 1922.

and useful UNITED STATES SAMUEL PEACOCK, OF WHEELING WEST VIRGINIA,

MENTS TO WHEELING STEEL & IRON A CORPORATION OF WEST VIRGINIA.

PATENT OFFICE.

sssrenon, BY mnsnn ASSIGN- COMIANY, OF WHEELING, WEST VIRGINIA,

APPARATUS FOR ANNEALING THIN STEEL SHEETS.

Specification of Letters Patent.

Patented Aug. 29, 1922.

Application filed November 9, 1920. Serial No. 422,814.

Wheeling, in the county of Ohio, and tate of West Vir inia, have invented certain new 'mprovements in Apparatus for Annealing Thin Steel Sheets; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. I

This invention relates to an apparatus for annealing thin sheets ofsteel preparatory to coating them with tin, and has for its object to provide a means by which said annealing may be accomplished out of contact with the air, and in a manner more expeditious and less costly than has been heretofore proposed.

With these and other objects in view the invention consists in the novel details of construction, and combinations of parts constituting the apparatus, all as will be more fully hereinafter disclosed and particularly pointed out in the claims.

Referring to the accompanaying drawings forming a part of this specification, in which like numerals designate like parts in all the views:

Figure l is a sectional View of an apparatus made in accordance with this invention;

Figure 2 is a sectional View of the base portion of the apparatus detached from the cover portion thereof;

Figs e 3 is a plan View tially broken away, the parts shown Figure in order that the precise inventio be the more ciearly understood, it As is ell known in the coating of thin steel sheets with tin, it is necessary to thoroughly desca: sheets before subjecting to the bath, and that this involves an an neali tep to soften the plates, then a pickling ii to deprive said sheets of their the surfaces of the sheets; then a annealing process to take out the s produced by rolling and then a second pickling operation to get rid of the oxides formed during the second annealing operat on,

Fro the foregoing it will be seen that if either the annealing steps could be carinto the tin plate of commerce,

like foundation upon the brick 2;

as shown, and also with ried out in an atmosphere devoid of oxygen such as a substantial vacuum, or in an atmosphere of a reducing gas, the oxides would not be formed on the plates, and that therefore, the process of coating with tin could be very much lessened in cost. Accordingly, the object of this invention, more specifica ly stated, is to provide an apparatus by which thin steel sheets to be converted nealedwithout suffering the objectionable oxidation heretofore experienced.

Referring to the accompanying drawings forming a part of this specification,

1 indicates any suitable supporting base preferably of iron; 2 a foundation of refractory non-conducting material such as fire brick resting upon the base 1; 3 a plate preferably of metal resting and 4 non-conducting sheets such as asbestos resting upon the plate 3. Located upon the asbestos sheets 4: are the piles 5, 6 and 7 of thin steel sheets to be annealed. The said foundation plate 1 is provided with suitable supports or legs 8, any suitable means such as 9 by which it can be readily, together with its burden, moved from place to place by means of a crane or other lifting apparatus 19, ll, 12, and 13 represent a plurality of metal hoods or covers adapted to completely enclose the packs of steel sheets 5, 6, 7; and 1d,,l5, and 16 represent air spaces bell, 12 and 13 in orthe - drawings.

25 and 26 represent clamp members pivoted as at 27 and provided with the screw means 28 adapted to clamp the feet like members 20, 21, $22, and 23 tightly against each other and against the pad 24:, so as to make the enclosure air-tight,

Supported from the enclosing members as by the rod 30 is the wire supporting means may be an-v 31 carrying a plurality of electrical resistance heating members 32, 33, 34c, and 35 adapted to fit the spaces between the packs of plates 5, 6, and 7 and between said packs and the inner wall of the enclosing member 10, as illustrated. Said member 31 as well as said enclosing members 10, 11, 12, and 13 are further supported and bound together by the central rod 36 provided with the ring like member 37 adapted to be engaged by a lifting crane so that the cover members 10, 11, 12, and 13, the heating members 32, 33, 34, and 35, and all other parts that are rigid with said cover members may be bodily lifted ofi" the base member 1 and from over the packs of plates 5, 6, and 7, to err pose said plates for a ready removal after the annealing process has been completed.

40 represents a pipe which enters the enclosure and it may serve as a means for exhausting said enclosure of air or of introducing into said enclosure a reducing such as CO, or an inert gas such as nitrogen. d1 represents a pressure gauge to indicate the degree of vacuum, and a thermometer, not shown, is also conveniently provided in order to indicate the temperature existing at any particular time on the interior of said enclosure.

The operation of this invention will be clear from the foregoing, but may be briefly summarized as follows: The packs of sheets 5, 6, and 7 are stacked upon the metal base plate 3 as indicated, the asbestos sheets 4: being interposed as illustrated, to prevent the hot sheets from sticking to the plate 3, whereupon for convenience of treatment and to save space, in the rolling mills, the base plate 1 together with said packs 5, 6 and 7 is picked up by a crane not shown, which lowers the said base plate 1 to the position selected, whereupon the same crane, or another, picks up the cover members 10, 11, and 12 together with the heating members 32, 33, 34, and 35, and lowers the same down over the packs 5, 6, and 7 into the positions indicated in Figure 1, whereupon the clamping members 25 are adjusted, all around the base plate 1, and an air tight joint is made therewith, as will be readily understood.

Then a vacuum is created on the interior of the cover members by means of suction through the pipe 40, or producer gas or nitrogen gas is let into said space, whereupon current is turned on through the leads and 46, and the resistors 32, 33, 34:, and 35 are heated up. Heat is maintained at the proper well known temperature and for the well known time necessary to properly anneal said plates, whereupon the current is turned off and it will be found that the asbestos plates will have prevented the lower sheets or the packs 5, 6 and 7 from sticking to the metal plate 3, and it will be found that the said metal plate 3 will have pre' vented the softening or the deterioration and depression of the fire brick 2 under the relatively high temperatures employed.

The air spaces 141-, 15, and 16 will prevent the escape of heat to a material extent and therefore the process will be carried out with a minimum expenditure of heat energy.

in order that the lower sheets of the packs 5, 6 and 7 may be properly heated up the resistor members. are conveniently located within the metal plate 3 and serve to transmit heat through the relatively thin asbestos sheets 1 to said lower sheets or the packs 5, ti, and 7.

It is obvious that those skilled in the may vary the details of construction, as well as the arrangement of parts without departing from the spirit of the invention, and therefore 1 do not wish to be limited to the above disclosure except as may be required by the claims.

What is claimed is:

1. In an apparatus for annealing thin sheets of steel, the combination of a metal base plate; a mass of refractory non-heat conducting material carried by said base plate; means for supporting said steel sheets in packs on said mass; a heat insulating cover comprising a plurality of metal members spaced apart and provided with air spaces between them; enclosing said mass and packs of sheets; means to form an airtight joint between said base plate and said cover; means to exhaust the air from around said packs; and electric heating means for heating said packs to an annealing temperature, substantially as described.

2. In an apparatus for annealing thin sheets of steel, the combination of metal base plate; a mass of refractory non heat conducting material carried by said base plate; means comprising a metal slab having spaces to receive electric heating means for supporting said steel sheets in packs on said mass; a heat insulating cover composed of a plurality of members separated by air spaces enclosing said mass and packs of sheets; means to form an air tight joint between said base plate and said cover; means to exhaust the air from around said packs; and means comprising electric circuit connections and electric resistors for heating said packs to an annealing temperature, substantially as described.

In testimony whereof I aflix my signature.

' SAMUEL PEACUCK. 

